1. Field of Invention
The present invention relates to a structure for absorbing a joint (splice) created in a branch section when electrical signals are distributed and picked up by distributing electrical wires which are made to branch from electrical wires or a piece of wire harness.
2. Related Art
Recently, there has been a tendency that the structure of electrical wires for signal use and pieces of wire harness for automobile use becomes more complicated in accordance with the progress of electronic control. Therefore, for example, as shown in FIG. 8, a plurality of pieces of sub-harness (A), (B), (C), . . . are made to branch from a plurality of positions of one piece of wire harness 1. Each piece of sub-harness is composed of distributing wires 2. A joint connector 3, which will be referred to as J/C in this specification hereinafter, arranged at the end portions of the distributing electrical wires 2 is connected with a joint box, which will be referred to as J/B in this specification hereinafter, which is an electrical connection box and also connected with other devices mounted on an automobile, so that electrical continuity can be attained for transmitting electrical signals.
In the above description, it is described that a plurality of pieces of sub-harness (A), (B), (C), . . . are made to branch from one piece of wire harness 1. However, the piece of wire harness 1 is actually produced in such a manner that the pieces of sub-harness (A), (B), (C), . . . are previously produced separately and jointed to each other into one piece of wire harness 1 in the latter production process.
FIG. 9 is a view schematically showing the wire harness illustrated in FIG. 8. In the case where the splices of the branch sections of the distributing electrical wires 2 in the pieces of sub-harness (A), (B), (C), . . . are absorbed, an electrical connection box such as J/B is commonly used. However, the following problems may be encountered in the actual condition. When the number of the branch sections is large and J/B is used for absorbing the splices of all the branches, the number of the distributing electrical wires 2 is much increased, so that the electrical circuit 2a in J/B becomes more complicated. As a result, the size of J/B itself is increased. Therefore, in the case of an automobile, the accommodating space of which is strictly limited, the costs of parts are raised due to the increase in the size of J/B, which is disadvantageous in all aspects. The degree of freedom of changing the design of the circuit is low in the case of the splice absorbing structure in which J/B is used. Accordingly, the productivity of the wire harness is deteriorated. As a result, the production cost is raised.
The simplest way to solve the above problems is to absorb the splice of the branch of the distributing electrical wires 2 without using J/B and J/C.
FIGS. 10A and 10B are views showing an electrical connector disclosed in Unexamined Utility Model Publication Sho.48-30785 which is proposed according to the above concept. In this case, the insulating box 4 is used instead of J/B and J/C, and the connecting terminals 6 are press-fitted into the square grooves 5 provided inside the insulating box 4. Due to the foregoing, the connecting terminals 6, which are adjacent to each other, are connected to each other with pressure, so that the splices can be absorbed and electrical continuity can be attained.
According to the splice absorbing connector disclosed in Unexamined Japanese Patent Publication Hei. 8-22859, there are used terminal insertion holes, which have not been used yet, out of a large number of terminal insertion holes provided in the existing J/B housing, and also there is used a bus bar of the fuse retainer. As a result, no specific J/C for absorbing the splice is used in the branch section, and the splice can be absorbed by using the existing J/B. Due to the above arrangement, the number of electrical wires can be reduced.
However, according to the related art disclosed in the above two patent publications, only the splices between the distributing electrical wires 2 of the pieces of sub-harness (A), (B), (C), . . . shown in FIG. 8 are absorbed, that is, consideration is not given to the absorption of the splice between one sub-harness and another sub-harness.
Therefore, it is an object of the present invention to provide a splice absorbing structure effective for reducing the number of electrical wires in a circuit and enhancing the productivity of the wire harness by absorbing the splice between the distributing wires and also the splice between the pieces of sub-harness without using J/B and J/C which are conventionally used for absorbing the splice of the electrical wires at the branch.
According to the first aspect of the present invention, there is provided a splice absorbing structure in which a plurality of pieces of sub-harness for distributing and picking up electrical signals from a piece of wire harness are made to branch, the pieces of sub-harness are respectively composed of a plurality of distributing electrical wires and splices of the distributing electrical wires at the branch section are absorbed, comprising: a connecting terminal crimped to an end portion of the distributing electrical wire at the branch section of the sub-harness, having a contact point elastic piece at the end portion; and a plurality of blocks, the number of which corresponds to the number of the pieces of sub-harness, capable of being engaged with and put on each other, having a plurality of terminal accommodating chambers arranged in parallel for accommodating the connecting terminals, wherein when the plurality of blocks are put on each other, the contact point elastic piece of the connecting terminal of the piece of sub-harness on one side comes into contact with the corresponding contact point elastic piece of the connecting terminal of the piece of sub-harness on the other side so that electrical continuity can be accomplished.
Due to the above structure, when the blocks corresponding to a plurality of pieces of sub-harness are put on each other, the connecting terminals accommodated in the blocks, which correspond to each other, come into contact with each other, so that the connecting terminals are electrically communicated with each other. In this way, the splice between the pieces of sub-harness can be absorbed, or the splice between a plurality of distributing electrical wires of one piece of sub-harness can be absorbed.
According to the second aspect of the present invention, there is provided a splice absorbing structure in which the block has a longitudinal opening and a bottom opening at the forward end of the terminal accommodating chamber for accommodating the contact point elastic piece of the connecting terminal, a top of the contact point elastic piece is engaged with the bottom opening on the other block side from the longitudinal opening when the blocks are put on each other, so that the top of the contact point elastic piece comes into contact with a base portion of the other contact point elastic piece, and a splice between one piece of sub-harness and the other piece of sub-harness can be absorbed.
In this case, since the longitudinal opening and the bottom opening are formed in the terminal accommodating chamber of each block, when the blocks are put on each other, the connecting terminals of the pieces of sub-harness accommodated in the lower block come into contact with the corresponding connecting terminals of the pieces of sub-harness accommodated in the upper block. Due to the foregoing, the splice between the pieces of sub-harness can be absorbed.
According to the third aspect of the present invention, there is provided a splice absorbing structure in which a lateral opening for communicating an end of one terminal accommodating chamber with an end of the other terminal accommodating chamber, which is adjacent to one terminal accommodating chamber, is formed in one of the blocks, and when the connecting terminal is accommodated in each terminal accommodating chamber under the condition that the contact point elastic piece is turned sideways, a top of one connecting terminal comes into contact with a base piece of the other connecting terminal via the lateral opening, so that a splice between one distributing electrical wire and the other distributing electrical wire, which is adjacent to one distributing electrical wire, can be absorbed.
In this case, in each block, there is provided a lateral opening for communicating the terminal accommodating chambers adjacent to each other. Therefore, for example, when the connecting terminals of the sub-harness are accommodated in one block under the condition that the contact point elastic pieces of the connecting terminals are turned sideways, the contact point elastic pieces come into contact with each other. Due to the foregoing, the splices between a plurality of distributing electrical wires of one piece of sub-harness can be absorbed.
According to the fourth aspect of the present invention, there is provided a splice absorbing structure in which the blocks, which are integrated into one body by being put on each other, are directly connected with other devices including a joint box, so that electrical continuity can be accomplished.
In this case, when a body in which the blocks are put on each other and integrated is directly connected with other devices, the splices can be collectively absorbed outside the joint box. Therefore, the circuit in the joint box can be reduced and simplified, and an increase in the size of the box can be prevented.
According to the fifth aspect of the present invention, there is provided a splice absorbing structure in which the uppermost block out of the blocks integrated into one body by being put on each other also functions as a cover of the longitudinal opening provided at the end of the terminal accommodating chamber, and a contact point elastic piece of the connecting terminal, which is accommodated in the terminal accommodating chamber, is a female terminal.
In this case, when the uppermost block is also used as a cover, the contact point elastic pieces of the connecting terminals accommodated in the block can be made to be female terminals. Therefore, when the male terminals such as rod-shaped tabs are inserted into the female terminals from the outside of the block so as to attain electrical continuity, the direct connecting structure to other devices such as the joint box can be effectively attained.